Flow development chamber for creating a vortex flow and a laminar flow

ABSTRACT

A pneumatic conveying system for conveying particulate material through a conduit that creates a strong laminar flow of materials and air surrounded by a boundary layer flow of air, such that long transport distances through dramatic elevation and directional changes can be achieved. Embodiments of the system include a blower assembly, an inlet conduit, an outlet conduit and a mixing chamber, wherein the mixing chamber includes an outer barrel, an inner barrel and an accelerating chamber. Low pressure air is supplied to the system by the blower assembly and mixed with particulate material. The air/material mixture is transported through the mixing chamber into the accelerating chamber and through the outlet conduit. In other preferred embodiments, the particulate material is mixed with the air in the accelerating chamber.

FIELD OF THE INVENTION

This invention is directed to apparatus and methods for conveyingvarying size particulate material through a conduit, such as, a pipe orhose, over long distances; more particularly, to apparatus and methodsthat convey material in a pneumatic material handling device.

BACKGROUND OF THE DISCLOSURE

Pneumatic conveying systems for transporting material through a conduithave been in use for years and are well known in the art. Over the yearsthe designs of these systems have changed to provide for greaterefficiency in operational cost and labor. For instance, early systemsutilized belt driven conveyors to transport materials from an inputhopper to a mixing chamber. Unfortunately, these systems wereinefficient in that the belt drives experienced many problems, such aswearing and breakage. Due, in part to problems experienced with beltsystems, pneumatic conveying systems were developed.

Generally, pneumatic conveying systems include a feed mechanism, suchas, an auger, for transporting the material to a mixing chamber. In themixing chamber, the material is entrained in pressurized air which issupplied into the mixing chamber through jets or air inlets. In somesystems, the material and air are mixed and accelerated in anaccelerating device, such as, a venturi pipe, which is connected to themixing chamber. The accelerated mixture is then transported out of theventuri pipe and into a conduit which conveys the materials to aspecified destination. Typically, conventional pneumatic conveyingsystems can transport material up to about 1,000 feet. The limiteddistance the material can be conveyed is due, in part, to the operatingpressure of the system and the instability of the material flow in theconduit.

Many other problems also exist with pneumatic conveying systems. Forexample, if excessive pressure builds up in the conduit, e.g., from ablockage in the conduit, gas and product back flow into the hopper. Thisback flow is known as "blowback". Further, as the material travelsthrough the conveying conduit, in earlier designs, and current designs,it strikes the walls of the conduit. This not only damages the walls ofthe conduit, but damages the material as well. Thus, problems of erosionof equipment and attrition of product are also present. Finally, manycurrent designs incur a high cost of operation due to the highrequirement of energy input to operate the system.

Many pneumatic systems have been developed to address differentproblems. For instance, the blowback problem, among others, wasaddressed in the system described in U.S. Pat. No. 4,711,607 to Wynoskyet al. In the Wynosky device, a rotating auger enclosed by a cylindricalbarrel transports particulate material towards the discharge end of thebarrel which resides within a plenum chamber. Pressurized gas isintroduced into the plenum chamber for creating a gas flow in a venturipipe, which is coupled at one end to the plenum chamber and at its otherend to a conduit used to transport the material. Measurements of thepressure differential between the plenum chamber and the conduit areused to monitor potential blowback problems. Further, this systemoperates at lower operating pressures than most systems, e.g., 12-15psi. Nonetheless, this system does not achieve a sufficiently stableflow of material through the conduit, which restricts the distance overwhich the material can be transported, including the ability totransport the material through elevational or directional changes.

U.S. Pat. No. 5,681,132 to Sheppard, Jr. describes an on-line pumpingunit designed to extend transport distances. In Sheppard, the pumpingunit includes a screw conveyor assembly coupled to a laminar flow,inductor assembly. In this system, the inductor assembly forms the coreof a linear accelerator apparatus used to extend transport distances.Nonetheless, this system does not teach how material can be conveyedover very long distances, such as, for example, a mile.

As shown from above, a need exists in the art for a system that requireslow energy input, reduces equipment wear, reduces product degradationand can transport materials for long distances, such as, a mile.Further, a need exists for a system that can convey materials throughdramatic high angle and vertical elevation and sharp directionalchanges. A need also exists for a system that can convey materialswithout plugging, and can further classify and mechanically drymaterials during processing.

SUMMARY OF THE DISCLOSURE

The instant invention is directed to a pneumatic material handlingsystem that allows the formation of a strong laminar flow of materialand air surrounded by a boundary layer flow of air, such that longtransport distances through dramatic elevation and directional changescan be achieved. The boundary layer flow of air protects the walls ofthe conducting conduit from assault by the conveyed material, therebyprotecting both the walls of the conduit and the conveyed material.Further, this system utilizes low pressure air to initiate theconduction of material, thereby dramatically reducing the operationalcosts of this system.

Preferred embodiments of the instant invention include a blowerassembly, an inlet and an outlet conduit. The blower assembly supplieslow pressure air to the system through the inlet, which in somepreferred embodiments receives both air and the particulate material tobe conveyed. The inlet is coupled to the flow developing device suchthat the air from the blower assembly passes into the mixing chamber.

The mixing chamber includes an outer barrel, an inner barrel and anaccelerating chamber, wherein the inner barrel is disposed within theouter barrel and wherein the outer barrel is coupled to the acceleratingchamber. The inner barrel of the mixing chamber can be either solid orhollow depending upon how materials are to be transported into thesystem. If materials are to be transported into the system entrained inair, then a solid or capped inner barrel is generally used. If materialsare to be transported by an auger or screw type conveyor, then a hollowinner barrel may be utilized and the auger or screw placed within thehollow inner barrel.

Typically, the air from the blower is passed tangentially over the inletsuch that the air, or air and material mixture, sets up a flow patternthat circulates and traverses the inner barrel towards the acceleratingchamber. Once in the accelerating chamber, a vortex flow is formed. Asthe flow moves through the accelerating chamber, the flow acceleratesand a boundary layer flow begins to form. The flow mixture then travelsout of the accelerating chamber into the outlet conduit which is coupledto the accelerating chamber. As the air/material mixture travels downthe outlet conduit, the vortex flow transforms into a laminar flowsurrounded by the boundary layer flow. The mixture is then transportedthe length of the outlet conduit until it reaches its destination.

In operation, embodiments of this invention operate at pressures between1-4 psi. One advantage of this lower pressure is that the operationalcosts are substantially reduced. A further advantage includes thereduction or substantial elimination of blowback problems.

Preferred embodiments of the instant invention are capable oftransporting material flows through dramatic elevation and directionalchanges. One advantage of this feature is that the system can beutilized in various types of space and over varying terrain.

Embodiments of this system can be scaled to varying sizes. Advantages ofvarying sizes of this system include the ability to build a system invirtually any size space and allows users to more appropriately meettheir needs, e.g., lower costs and lower production requirements andlower maintenance costs.

The material input into embodiments of this system are transported downthe conduit pipe in a laminar flow surrounded by a boundary layer flow.An advantage of the boundary layer flow is that it protects the conduitpipe from material as it passes down the pipe and further protects thematerial that is being transported.

Due to high air to particle ratio in the material flow, the system canbe shut down and restarted without the need to clear the lines, therebygaining an advantage of eliminating costly maintenance and line pluggingassociated with traditional technologies.

Additionally, embodiments of this system do not emit combustion orchemical pollutants. At least one advantage of this feature is that thesystem does not adversely affect the environment.

Further, materials transported down the conduit are mechanically, notthermally dried of surface moisture. This provides the advantage ofeliminating explosion hazards associated with current thermal dryers. Italso surface dries materials at considerable lower energy costs thanthermal dryers.

The above and other advantages of embodiments of this invention will beapparent from the following more detailed description when taken inconjunction with the accompanying drawings. It is intended that theabove advantages can be achieved separately by different aspects of theinvention and that additional advantages of this invention will involvevarious combinations of the above independent advantages such thatsynergistic benefits may be obtained from combined techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

The detailed description of preferred embodiments of the invention willbe made with reference to the accompanying drawings, wherein likenumerals designate corresponding parts in the figures.

FIG. 1 is a schematic of a preferred embodiment of a material conveyingsystem embodying features of the present invention.

FIG. 2 is a top view of a preferred embodiment of the mixing chamber andan inlet of the material conveying system of FIG. 1.

FIG. 3a is a plan view of a preferred embodiment of a cross section ofthe inlet coupled to the outer barrel of the material conveying systemof FIG. 1.

FIG. 3b is a side cross section of the inlet in FIG. 3a coupled to theouter barrel.

FIG. 4 is a preferred embodiment of the outer barrel of the materialconveying system of FIG. 1.

FIG. 5 is a cross section of a preferred embodiment of a solid innerbarrel of the material conveying system of FIG. 1.

FIG. 6 is a cross section of a preferred embodiment of an acceleratingchamber of the material conveying system of FIG. 1.

FIG. 7 is a schematic of another preferred embodiment of a materialconveying system utilizing a solid inner barrel and illustrating theflow paths of the air and material.

FIG. 8a is a preferred embodiment of a counterclockwise rotating airflow path through the outer barrel of FIG. 4.

FIG. 8b is a preferred embodiment of a clockwise rotating air flow paththrough the outer barrel of FIG. 4.

FIG. 9 is a cross section of a preferred embodiment of a hollow innerbarrel of the material conveying system.

FIG. 10 is a schematic of another preferred embodiment of a materialconveying system utilizing an auger within a hollow inner barrel andillustrating the flow paths of the air and material.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the instant invention are directed to anapparatus and a method for pneumatically conveying particulate materialthrough a conduit over long distances, such as, for example, a mile, andthrough elevation and directional changes. In some embodiments thesystem further mechanically dewaters/or and classifies the material bymass. With reference to FIG. 1, a preferred embodiment of an overallpneumatic material handling system 10 includes an air delivery system20, a material delivery system 40 and a mixing system 60. The airdelivery system 20 includes an air filter 22, an inlet silencer 24, ablower assembly 26, an outlet silencer 28 and a plurality of couplingpipes 30, 32, 34 and 36. The blower assembly 26 draws in air through theinlet filter 22 from the environment and filters out contaminants andother particulates. Inlet filters 22 are well known in the art andmanufactured, for example, by Nelson Industries under the UniversalSilencer name. Depending upon the environmental conditions, somepreferred embodiments do not require inlet filters as the air does notrequire filtering.

The inlet filter 22 is connected by coupling pipe 30 to the inletsilencer 24 which includes a cylindrical body having a first end and asecond end. The first end and the second end each include openings forpassing air into and out of the silencer 26. Silencers are also wellknown in the art and are manufactured, for example, by Nelson Industriesunder the Universal Silencer name.

The inlet silencer 24 is connected by coupling pipe 32 to the blowerassembly 26, which is any air blowing device that is capable ofdelivering low pressure air to the system. The blower assembly 26includes an inlet and outlet, wherein incoming air enters the blowerassembly 26 through the inlet and passes out of the blower assembly 26through the outlet. In preferred embodiments, a positive displacementblower generating air having a pressure capability of up to 12 psi maybe used. In one preferred embodiment, a Sutorbilt positive displacementblower, manufactured by Gardner Denver may be used.

The blower assembly 26 is connected by coupling pipe 34 to the outletsilencer 28.

Similar to the inlet silencer 24, the outlet silencer 28 includes acylindrical body having a first end and a second end, wherein the firstend and the second end each include openings for passing air into andout of the outlet silencer 28. Both the inlet and outlet silencers 24,28 are used to reduce excessive noise generated by the blower assembly26. If noise is not a consideration, then inlet or outlet silencers arenot necessary.

The coupling pipe 36 is connected to the second end of the outletsilencer 28 and extends towards the mixing system 60. In preferredembodiments, the coupling pipe 36 has an opening 37 for receivingmaterial from the material delivery system 40 as described below.

The material delivery system 40 preferably includes a hopper 42, arotary feeder 44 and a frame 46. The hopper 42 includes an open end 48and a chute 50. The open end 48 of the hopper 42 accepts incomingmaterial to be processed, such as, for example, coal or rubber.Typically, the open end 48 is large enough to accept large quantities ofmaterials of varying sizes. In one preferred embodiment, the open end 48is rectangular in shape, although any shape capable of acceptingincoming material is suitable.

The chute 50 of the hopper 42 is funnel shaped having a first end 52 anda second end 54. The first end 52 of the chute 50 resides adjacent theopen end 48 of the hopper 48 such that material falls into the portionof the chute 50 having the largest diameter. The open end 48 and thechute 50 can be manufactured as a single piece or can be separatelymanufactured and coupled together, such as, for example, by welding. Inpreferred embodiments, the hopper 42 is made from materials, such as,but not limited to, steel, aluminum or metal alloys, although anymaterial capable of accepting large quantities of materials is suitable.

The rotary feeder 44 includes a chamber 56 having a rotor, a dispensingchute 58 and a motor 59. The chamber 56 is a hollow barrel, wherein theinterior of the barrel is separated into segments by radial spokes. Thechamber 56 further includes a top openings and a bottom opening. The topopening of the chamber 56 is coupled to and communicates with the secondend 54 of the hopper 42. With reference also to FIG. 7, the dispensingchute 58 has an outlet disposed over the opening 37 of the coupling pipe36 such that material flowing through the dispensing chute 58 enters thecoupling pipe 36.

The motor 59 resides adjacent the rotary feeder 44 and causes the rotorto rotate. The motor 59 is any suitable device for driving the rotaryfeeder 44 and may be electrically driven or generator operated. Rotaryfeeders are well known in the art and are manufactured, for example, byBush & Wilton Valves, Inc. Some preferred embodiments do not require arotary feeder 44.

The frame 46 provides support to the hopper 42 and rotary feeder 44. Theframe includes a plurality of legs, wherein the open end 48 of thehopper 42 is coupled to the legs, such as, for example, by welding. Somepreferred embodiments do not require a frame 46.

With reference to FIGS. 2, 3a, 3b and 4, the mixing system 60 includesan inlet conduit 62, a mixing chamber 64 and an outlet conduit 66.Preferably, the inlet conduit 62 is a pipe, although any conduit, suchas, for example, a hose, which is capable of receiving air and/ormaterial is suitable. The inlet conduit 62 should preferably be capableof receiving large amounts of particulate material at high rates. Forinstance, in one preferred embodiment, the inlet conduit 62 is capableof receiving material up to 3" in diameter at a rate of 500 tons/hour.For greater volumes, multiple systems can be used.

As shown in FIG. 3b, the inlet conduit 62 includes a first end 68, asecond end 70 and a coupling flange 72, wherein both the first end 68and the second end 70 are open. Preferably, the diameter d_(inlet) ofthe inlet conduit 62 is substantially constant throughout the distancebetween the first end 68 and a point A at which the inlet conduit 62couples to the mixing chamber 64. Preferred embodiments typically havediameter sizes of 2", 4", 6", 8", 10", 12" and 18" as it has been foundthat most materials with diameter sizes up to 5" can pass through inletshaving these size diameters.

The coupling flange 72 extends radially outward from the first end 68 ofthe inlet conduit 62 and has a plurality of opening 23 for receivingfasteners. The coupling flange 72 is coupled to the second end of thecoupling pipe 36 such that the inlet conduit 62 is in fluidcommunication with the coupling pipe 36 and can receive incoming air andparticulates.

Typically, the inlet conduit 62 is cylindrical in shape, although anyshape, such as, for example, a rectangle or octagon, which is capable ofpassing air and material is suitable. In preferred embodiments, theinlet conduit 62 is made from durable materials, such as, for example,aluminum, metal alloys or steel, although any material capable ofcontacting a wide variety of materials without sustaining substantialdamage is suitable.

The mixing chamber 64 further includes an outer barrel 74, an innerbarrel 76 and an accelerating chamber 78. With reference also to FIG. 4,the outer barrel 74 includes a hollow interior 80 having an innerdiameter d_(ob), an opening 71 (see FIG. 3b), a first end 84 and asecond end 86.

The hollow interior 80 is capable of receiving air and material. Thesecond end 71 of the inlet conduit 62 (FIG. 3b) is coupled around theopening 70 such that the hollow interior 80 of the mixing chamber 64(FIG. 4) is in fluid communication with the inlet conduit 62 of FIG. 3b.

Typically, the outer barrel 74 is cylindrical in shape. In preferredembodiments, the outer barrel 74 is made from durable materials, suchas, for example, aluminum, metal alloys or steel, although any materialcapable of contacting a wide variety of materials without incurringsubstantial damage is suitable.

With reference also to FIG. 5, the inner barrel 76 includes a firstmember 88, a second member 90 and a mounting flange 92. The first member88 includes a first end 94, a second end 96 and an outer surface 98. Theinner barrel 76 is disposed within the hollow interior 80 of the outerbarrel 74 (FIG. 2). In one preferred embodiment, the inner barrel 76 issolid. In other preferred embodiments, described below, the inner barrel76 is hollow.

Preferably, the first member 88 (FIG. 5) is cylindrical in shape.Further, the diameter d_(ib) of the first member 88 is preferablyconstant between the first end 94 and the second end 96.

The mounting flange 92 is a plate of any shape, such as, for example, adisk or rectangular element which is coupled to the first end 94 of thefirst member 88. In some preferred embodiments, the mounting flange 92and the first member 88 are formed as a single piece. The mountingflange 92 also connects to the first end 84 of the outer barrel 74.

The second member 90 of the inner barrel 76 includes a cylindricalsection 100 and a hemispherical end portion 102. The cylindrical section100 is coupled to the second end 96 of the first member 88.

The hemispherical end portion 102 resides adjacent the cylindricalsection 100. In some preferred embodiments, the hemispherical endportion 102 and the cylindrical section 100 are formed as a singleelement. Although this preferred embodiment depicts a hemisphericallyshaped end portion, any geometry from a flat plate to a hemisphericallyshaped cap is suitable. Typically, the radius of the hemispherical endportion 102 is substantially equivalent to the radius of the firstmember 88 and the cylindrical section 100 (FIG. 5 not drawn to scale).

Preferred embodiments of the inner barrel 76 are made from materials,such as, but not limited to, steel, metal alloys and aluminum. However,any material capable of contacting a wide variety of materials withoutincurring substantial damage is suitable.

With reference also to FIG. 6, the accelerating chamber 78 includes anouter cylindrical section 104 and a conical section 106. The outercylindrical section 104 includes a first end 108 and a second end 110,wherein the diameter d₁ is preferably constant between the first end 108and the second end 110. The first end 108 of the outer cylindricalsection 104 of the accelerating chamber 78 is coupled to the second end86 of the outer barrel 74.

The conical section 106 includes a first end 112 and a second end 114,wherein the first end 112 is coupled to the second end 110 of thecylindrical section 104. The diameter between the first end 112 and thesecond end 114 of the conical section decreases in size from the firstend 112 to the second end 114. In one preferred embodiment, the conicalsection 106 is a standard concentric pipe reducer. In another preferredembodiment, the accelerating chamber 78 does not include the cylindricalsection 104, rather, the accelerating chamber is a cone, such as, forexample, a flat rolled cone, preferably having an angle of about30°-55°.

With reference to FIGS. 6 and 7, the outlet conduit 66 is a process pipehaving an outside diameter d_(oc1) and an inside diameter d_(oc2) forconveying material to a predetermined destination. The outlet conduit 66is coupled to the second end 112 of the conical section 106 of theaccelerating chamber 78 such that the material and air mixture is passedfrom the accelerating chamber 78 into the outlet conduit 66. The outletconduit 66 can extend for long distances, such as for example, greaterthan 1 mile.

Referencing FIGS. 1 and 7, in operation, the blower assembly 26 isturned on and air is drawn into the inlet filter 22. The air is cleanedof particulates and passes into the inlet silencer 24. The air passesthrough the inlet silencer 24 and enters the blower assembly 26. Theblower assembly 26 passes air having up to 12 psi into the outletsilencer 28. As stated above, the inlet and outlet silencers reduce theamount of noise generated by the blower assembly 26. After the airpasses through the outlet silencer 28, it exits into coupling pipe 36and travels past the material delivery system 40.

Either before, after or during the time that the air delivery system 20has begun operation, material is input into the open end 48 of thehopper 42 or other feeder device. The material passes through the openend 48 and into the chute 50 wherein the material may accumulate untilfed out by the rotary feeder 44.

The rotary feeder 44 turns at a predetermined rate such that onlyspecified quantities of material are released from the feeder 44. Thematerial drops through the dispensing chute 58 and through the openingin the coupling pipe 36.

As air passes through the coupling pipe 36, it picks up the material andentrains the material in the air flow. The material and air continuethrough the coupling pipe 36 and enter the first end 68 of the inletconduit 62. With reference also to FIG. 8a, after entering the inletconduit 62, the material/air mixture preferably flows around the innersurface of the outer barrel 74. This is in contrast to the turbulentflows created in current pneumatic systems. It is believed that thetangential input of the air/material mixture along the interior of theouter barrel 74 leads to the development of the steady counterclockwiseflow (when viewed from the back of the chamber) of the mixture in theouter barrel 74. With reference to FIG. 8b, in other preferredembodiments, the inlet conduit 62 may be mounted to the opposite side ofthe outer barrel 74 such that the air/material mixture flows in aclockwise direction in systems in use below the equator due to theCoriolis effect. The counterclockwise flow is preferred north of theequator due to the fact that a natural vortex rotates counterclockwise.However, clockwise rotations can also be established north of theequator.

As more air and material flows into the mixing chamber 64, theair/material mixture traverses the length of the inner barrel 76 whileflowing counterclockwise around its outer surface 98 until it reachesthe hemispherical end portion 102 in FIG. 5.

After passing over the hemispherical end portion 66 the air/materialflow preferably forms a vortex 77, which is a combination of a sink flowand an irrotational vortex flow, and is accelerated through theaccelerating chamber 78 (FIG. 7). As the flow traverses the length ofthe accelerating chamber 78, Taylor vortices, in the form of a boundarylayer flow 79 of air, begins to form along the inner surface of theaccelerating chamber 78 such that the forming boundary layer flow 79surrounds the vortex flow 77. Typically, the boundary layer flow is0.125"-0.25" thick. Generally, no material is found in the boundarylayer flow 79, however, moisture is typically found in the boundarylayer.

The vortex flow 77 and forming boundary layer flow 79 exit theaccelerating chamber 78 through the second end 114 of the conicalsection 106 and enter the outlet conduit 66. As the flows 77, 79 exitthe accelerating chamber 78, the boundary layer flow 79 is aboutsubstantially formed and traverses down the outlet conduit 66 atvelocities of about less than 5 mph. The air flowing in the boundarylayer 79 preferably circulates around the inner circumference of theoutlet conduit 66.

The vortex 77 continues to travel for about 10-60 feet within the outletconduit 66 prior to a laminar flow 81 forming. The length of the vortexcan vary with the volume of air or product mass. In contrast to the slowmoving boundary layer flow 79, the air in the laminar flow 81 is movingat velocities of about 50-60 mph. The material, which is travelingwithin the laminar flow 81, can travel at velocities of about 100 mph.Further, the denser material is traveling in the center of the laminarflow 81 while progressively less dense material travels in the outerportion of the laminar flow 81. As previously mentioned, moisturetravels closest to, or in, the boundary layer flow 79.

In addition to the features discussed above, some preferred embodimentsof the instant invention further include a controller 116 (see FIG. 1).In some preferred embodiments, the controller 116 is a computer, suchas, for example, a personal computer, although any device capable ofregulating the amount of air and material input into the system issuitable. To control the amount of air input into the system, somecontrollers include a variable frequency drive (not shown) which helpsto automatically regulate the air flow for a given material. Othercontrollers allow manual regulation by the user or allow the systemparameters to be set to deliver a constant flow.

In addition to regulating the amount of air input, the controller 116may regulate the speed of the rotor which feeds material into thesystem. Typically, an optimal ratio exists between the type of materialto be input and the amount of air required for a suitable air/materialratio such that a stable flow of material can be created to transportthe material. For instance, for coal, the optimal ratio of air to coalis 1.75 to 1.0 volume of air to weight of coal.

Other preferred embodiments, also include a moisture collection system132 and a decelerator 134. With reference to FIG. 7, the moisturecollection system 132 is a vacuum system coupled to the outlet conduit66 at various locations. The moisture collection 132 system pullsmoisture off of the boundary layer flow 79 as it travels down the outletconduit 66. Cyclones can also be used to remove the moisture in otherpreferred embodiments.

The decelerator 134 slows down the material which is moving through theoutlet conduit 66. The decelerator 134 is either a collection bin or acyclone system. Cyclones are well known in the art and are manufacturedby, for example, Fisher-Klosderman, Inc.

In some preferred embodiments, the sizing of the various elements arespecifically related to each other. It will be appreciated that this isnot intended to restrict the sizing of any of the elements, but ratherto illustrate relationships between elements found in some preferredembodiments.

In one preferred embodiment, many of the elements are sized with respectto the diameter of the outlet conduit. Preferably, the diameterd_(inlet) of the inlet conduit 62 is substantially equivalent to theinner diameter d_(oc2) of the outlet conduit 66. This equivalency indiameters increases the likelihood that materials passing into thesystem are capable of passing out of the system. The precise diameter ofthe inlet conduit 68 is, in part, determined based upon the type ofmaterial and the rate of material to be input. For instance, materialssuch as, for example, coal or rubber, less than 1" in size preferablyrequire an inlet diameter of 4" for an input rate of 5 tons/hour.

Regarding the outer barrel 74, the inner diameter of the hollow interior80 of the outer barrel 74 ranges from about 1.5 to 2.5 times the size ofthe inner diameter d_(oc2) of the outlet conduit 66. In one preferredembodiment, the inner diameter of the hollow interior 80 is, forexample, 8", which is 2.0 times as large as the inner diameter of theoutlet conduit 66.

Similar to the outer barrel proportions, the outer diameter d_(ib) ofthe inner barrel 76 ranges from about 1.0 to 1.5 times the size of theinner diameter of the outlet conduit 66. In one preferred embodiment,the outer diameter of the inner barrel 76 is 5", which is 1.25 times thesize of the inner diameter of the outlet conduit 66.

With respect to the accelerating chamber 78, the diameter at the firstend d₁ (FIG. 6) is equal to the diameter d_(ob) of the outer barrel 74.The diameter of the second end 114 of the conical section 106 issubstantially equivalent to the inner diameter of the outlet conduit 66.The length of the conical section 4 is preferably about 1.5 to 2.5 timesthe inner diameter at the outlet conduit 66. In one preferredembodiment, the length of the conical section 106 is about 8", which isabout 2.0 times the size of the inner diameter of the outlet conduit 66.

The diameters of the various elements are not the only proportionallysized aspects of features of preferred embodiments. For instance, thelength of the outer barrel 74 preferably ranges from about 2.0 to 4.5times the size of the outer diameter d_(oc1) of the outlet conduit 66.Further, the opening 82 in the outer barrel 74 which couples to thesecond end 70 of the inlet conduit 62, is typically 1.5 times thecross-sectional area of the inlet conduit 62 (see FIG. 3b). This allowsfor faster transport of material into the hollow interior 80 of theouter barrel 74.

Regarding the inner barrel 76, the length I_(ic) of the inner barrel 76is slightly longer than the length of the outer barrel 74. In preferredembodiments, the inner barrel 76 is longer by about 0.25" to 0.5". Inone preferred embodiment, the length of the inner barrel 76 is 0.25"longer than the length of the outer chamber 44, specifically, the lengthis 12.25".

With respect to FIG. 10, an alternative embodiment of the instantinvention includes an air delivery system 20, a material delivery system40 and a mixing system 60. Reference is made to the discussions aboveregarding the air delivery system 20.

In this preferred embodiment, the material delivery system 40 includes ahopper 42, wherein the hopper 42 includes an open end 48 and a chute 50.Reference is made to the discussions above regarding the open end 48 andthe chute 50.

The mixing system 60 includes an inlet conduit 62, a mixing chamber 64and an outlet conduit 66. Reference is made to the discussions aboveregarding the inlet conduit 62 and the outlet conduit 66.

The mixing chamber 64 further includes an outer barrel 74, an innerbarrel 76 and an accelerating chamber 78, wherein the outer barrel 74and accelerating chamber 78 have been previously discussed.

Also with reference to FIG. 9, the inner barrel 76 includes a hollowinterior 118, a first end 120, a second end 122, a coupling position124, and a mounting flange 92. The first end 120 of the inner barrel 76is open and includes an annular flange 126 extending radially outwardtherefrom. The first end 120 must be sized to accept the proper sizedauger.

The second end 122 of the inner barrel 76 is also open and furtherincludes beveled ends 128, wherein the ends are beveled inwardly. Thediameter of the second end 122 is substantially equivalent to thediameter of the first end 120 such that material input into the innerbarrel 76 is capable of exiting the inner barrel 76.

Reference is made to the discussions above regarding the mounting flange92. However, in this embodiment, the mounting flange 92 is coupled tothe inner barrel 76 at the coupling position 124. The coupling position124 is determined, in part, from the length of the outer barrel 74,wherein the distance between the coupling position 124 and the secondend 122 will be about the length of the outer barrel 74 plus an amountin the range of about 0.25"-0.5". In one preferred embodiment, the innerbarrel 74 extends 0.25" longer than the outer barrel 76.

With reference to FIG. 10, an auger 130 or screw type conveyor having anopening 127 and an annular flange 129 is disposed within the hollowchamber 118 to move material into the system. Flange 129 of the augercouples to flange 126 of the inner barrel 76. Suitable augers are wellknown in the art. An auger or screw type material transport is typicallyused in instances where the material to be conveyed is hot or can damageor destroy the outer surface 98 of the inner chamber 76 as the auger canbe treated for specific needs, e.g., chemically treated or heat treated.

In these systems, material falls from the second end 54 of the hopper 42and is deposited in the auger 130 through the opening 127. The auger 130moves the material from the point of deposit to the second end 122 ofthe inner chamber 76. The air, which has entered the system in the samemanner as described above, picks up the material at the second end 122of the inner chamber 76. The remainder of the process, as describedabove, is the same.

The boundary layer and laminar flows established by preferredembodiments of this invention are capable of maintaining a steady stateflow in excess of one mile. Further, these flows can experienceelevation changes, such as, for example, 200 foot vertical anddirectional changes, such as, for example, 90° to 180°, without loss ofthe steady state flows. Further, due to the relatively low pressure ofthe input air coupled with the configuration of the mixing chamber 64,this system achieves operating pressures of about 1-4 psi though thesystem can operate at pressures up to the maximum obtained by the airsystem, such as, for example, 12 psi. In addition to reducing blowbackproblems and increasing distances traveled by the materials, this systemhas substantially lower operating costs.

In one preferred embodiment, a mile of 2" pipe, coupled together every20 feet, successfully transported coal through the conduit to thepredetermined destination without interruption of the laminar flow, asevidenced by the steady state of the output from the conduit. Further,this piping was laid along an uneven and curved pathway such that thematerials traveled through elevational and directional changes. Inanother instance, 75 tons per hour of coal were moved in a 100' verticaldirection and through a 180 degree turn.

Due to the extremely high velocities attained by the material within theflows, laminar and vortex, materials exiting the conduit have beendewatered during transport. Indeed, a product of 3" or less can be driedto within 10% or less of its surface moisture. In some preferredembodiments, a vacuum is coupled to the conduit outlet 66 at variouslocations and enhances the moisture removal ability of the process.Further, as the materials are all moving at the same velocity, but havedifferent mass, therefore different momentums, the particulate materialwill naturally separate out according to mass. Thus, one benefit of thissystem includes the separation of input materials upon discharge. Acollection bin for different particulates need only be placed near theoutlet 66 to capture the particulate material upon exiting the system.

The measurements given in this disclosure are not intended to limit theinvention. Indeed, variations in the size of this system have proveneffective and this system is capable of operating as a free standingunit or a cabinet mounted system, e.g., on a trailer which can betransported.

Although the foregoing describes the invention with preferredembodiments, this is not intended to limit the invention. Rather, theforegoing is intended to cover all modifications and alternativeconstructions falling within the spirit and scope of the invention.

We claim:
 1. A pneumatic, material handling system comprising:an outerbarrel having an inlet end, an outlet end and an interior cylindricalsurface; an accelerating chamber having an inlet end and an outlet end,the inlet end of the accelerating chamber extending concentrically fromthe outlet end of the outer barrel, the accelerating chamber having aconical interior surface that converges in a direction from the inletend to the outlet end; an inner barrel having an exterior cylindricalsurface with a first end and a second end, the inner barrel locatedconcentrically inside the outer barrel, wherein the outer barrel, theinner barrel and the accelerating chamber are arranged to form asubstantially unobstructed annular space between the interiorcylindrical surface of the outer barrel and the exterior cylindricalsurface of the inner barrel, the annular space extending from the firstend of the exterior cylindrical surface of the inner barrel to theconical interior surface of the accelerating chamber; an inlet conduitmounted to the inlet end of the outer barrel to direct gas through theouter barrel into the annular space; wherein the first end of theexterior cylindrical surface of the inner barrel is adjacent the inletconduit and the second end of the exterior cylindrical surface of theinner barrel is adjacent the accelerating chamber; wherein the inletconduit is directed tangentially to the interior cylindrical surface ofthe outer barrel to set up a flow pattern in the annular space such thatgas flowing from the inlet conduit into the outer barrel will circulatearound the inner barrel and traverse the annular space from the inletend of the outer barrel toward the outlet end of the outer barrel;wherein the inner barrel is closed at the downstream end.
 2. Anapparatus as claimed in claim 1, wherein the inner barrel is solid. 3.An apparatus as claimed in claim 1, wherein the downstream end of theinner barrel is hemispherical in shape.
 4. An apparatus as claimed inclaim 1, wherein the downstream end of the inner barrel is flat inshape.
 5. The handling system of claim 1 wherein the second end of theexterior cylindrical surface of the inner barrel is closer to the inletend of the accelerating chamber than to the outlet end of theaccelerating chamber.
 6. The material handling system of claim 1,whereinthe second end of the exterior cylindrical surface of the inner barrelis adjacent a substantially unobstructed downstream area such that thecirculating flow of the gas in the annular space is converted to avortex flow in the accelerating chamber when gas is supplied to thesystem.
 7. A pneumatic, material handling system comprising:a flowdevelopment chamber; a gas delivery system including a gas deliveryconduit to deliver gas to the flow development chamber; a materialdelivery system including a housing to hold material to be conveyed anda material delivery conduit connected to the gas delivery conduit at alocation prior to the flow development chamber to deliver the materialto the gas delivery conduit such that gas and material are combinedprior to entering the flow development chamber during operation of thesystem; wherein the flow development chamber includes: an outer barrelhaving an inlet end, an outlet end and an interior cylindrical surface;an accelerating chamber having an inlet end and an outlet end, the inletend of the accelerating chamber extending concentrically from the outletend of the outer barrel, the accelerating chamber having a conicalinterior surface that converges in a direction from the inlet end to theoutlet end; an inner barrel having an exterior cylindrical surface witha first end and a second end, the inner barrel located concentricallyinside the outer barrel, wherein the outer barrel, the inner barrel andthe accelerating chamber are arranged to form a substantiallyunobstructed annular space between the interior cylindrical surface ofthe outer barrel and the exterior cylindrical surface of the innerbarrel, the annular space extending from the first end of the exteriorcylindrical surface of the inner barrel to the conical interior surfaceof the accelerating chamber; an inlet conduit mounted at one end to thegas delivery conduit and at the other end to the inlet end of the outerbarrel to direct gas from the gas delivery system and material from thematerial delivery system through the outer barrel into the annularspace; wherein the first end of the exterior cylindrical surface of theinner barrel is adjacent the inlet conduit and the second end of theexterior cylindrical surface of the inner barrel is adjacent theaccelerating chamber; wherein the inlet conduit is directed tangentiallyto the interior cylindrical surface of the outer barrel to set up a flowpattern in the annular space such that gas flowing from the inletconduit into the outer barrel will circulate around the inner barrel andtraverse the annular space from the inlet end of the outer barrel towardthe outlet end of the outer barrel; wherein the inner barrel is closedat the downstream end.
 8. The handling system of claim 7 wherein the gasdelivery system includesa blower assembly, wherein the blower assemblysupplies gas to the chamber.
 9. The material handling system of claim7,wherein the second end of the exterior cylindrical surface of theinner barrel is adjacent a substantially unobstructed downstream areasuch that the circulating flow of the gas in the annular space isconverted to a vortex flow in the accelerating chamber when gas issupplied to the system.
 10. A pneumatic, material handling systemcomprising:an outer barrel having an inlet end, an outlet end and aninterior cylindrical surface; an accelerating chamber having an inletend and an outlet end, the inlet end of the accelerating chamberextending concentrically from the outlet end of the outer barrel, theaccelerating chamber having a conical interior surface that converges ina direction from the inlet end to the outlet end; an inner barrel havingan exterior cylindrical surface with a first end and a second end, theinner barrel located concentrically inside the outer barrel, wherein theouter barrel, the inner barrel and the accelerating chamber are arrangedto form a substantially unobstructed annular space between the interiorcylindrical surface of the outer barrel and the exterior cylindricalsurface of the inner barrel, the annular space extending from the firstend of the exterior cylindrical surface of the inner barrel to theconical interior surface of the accelerating chamber; an inlet conduitmounted to the inlet end of the outer barrel to direct gas through theouter barrel into the annular space; wherein the first end of theexterior cylindrical surface of the inner barrel is adjacent the inletconduit and the second end of the exterior cylindrical surface of theinner barrel is adjacent the accelerating chamber; wherein the inletconduit is directed tangentially to the interior cylindrical surface ofthe outer barrel to set up a flow pattern in the annular space such thatgas flowing from the inlet conduit into the outer barrel will circulatearound the inner barrel and traverse the annular space from the inletend of the outer barrel toward the outlet end of the outer barrel;wherein the inner barrel is solid.